The present invention relates to a display method and a display apparatus. Especially, the present invention relates to an ultra high definition apparatus and a display apparatus with a high drive frequency.
A line-sequential scanning method, in which the scanning pulse is applied to each scanning electrode at the interval of one frame once, is adopted in the drive for the conventional TFT active matrix type liquid crystal display.
As one frame time, about {fraction (1/60)} seconds are frequently used. Usualy, the scanning pulse is applied from the upper part of the panel to the bottom part while shifting timing one by one. Therefore, the time width of the scanning pulse is about 35 μs, because 480 gate wirings are scanned during one frame in the liquid crystal display apparatus with the pixels of 640×480 dots.
On the other hand, a liquid crystal drive voltage to apply to the liquid crystal of the pixels corresponding to one line to which the scanning pulse is applied is simultaneously applied to the signal electrodes in synchronization with the scanning pulse. It is necessary to input the pixel signal which corresponds to the liquid crystal drive voltage applied to the liquid crystal of the pixels of the next row to all signal electrodes in time that the scanning pulse is applied to the scanning electrodes at the previous and one row. In the liquid crystal display apparatus of 640×480 dots, the pixel signals corresponding to 640 rows are input during the time width of the scanning pulse (about 35 μs). Therefore, the time allocated to one pixel signal is about 35 μs/640=55 ns.
In the selection pixel to which the gate pulse is applied, the gate electrode voltage of a TFT connected to scanning electrode increases. Therefore, TFT becomes an on-state. At this time, the liquid crystal drive voltage is applied to the display electrode via source-to-drain of TFT. As a result, the pixel capacity is charged during the above-mentioned 35 μs. The pixel capacity is the total capacity of the liquid crystal capacity formed between the display electrode and the opposed electrode and the load capacity arranged in the pixel. By repeating this charge operation, the liquid crystal applied voltage is repeatedly applied to the pixel capacity in the whole area of the panel each frame-time.
The conventional TFT active matrix type liquid crystal display apparatus is driven as described above. Therefore, when the display becomes high definition, and the number of pixels to be displayed increases, the time width of the scanning pulse and the time allocated to input one pixel signal shorten. That is, it is necessary to charge the pixel capacity in a short time. Further, it is necessary to input the pixel signal in a shorter time.
On the other hand, it is necessary to shorten one frame time further to support the high-speed animation. Also in this case, the time width of the scanning pulse and the time allocated to input one pixel signal shorten.
As mentioned above, it is necessary to charge the liquid crystal drive voltage to the pixel capacity in a short time to display the high definition picture or high-speed animation. The liquid crystal drive voltage is supplied to the pixel capacity by driving circuit provided at the edge portion through signal electrode lines. In that case, the delay is caused in the liquid crystal drive voltage supplied to the pixel capacity by the wiring delay in the signal electrode line. It is necessary to set the time width of the scanning pulse very long compared with this delay time in order to display the normal picture.
However, because the time width of the scanning pulse cannot be set enough long in the prior art, the normal high definition picture or high-speed animation cannot be displayed.
Further, it is necessary to input in a shorter time the pixel signal to the liquid crystal display apparatus, in order to display a high definition picture or high-speed animation. That is, it is required to increase the frequency of the signal input to liquid crystal display apparatus. However, there is a problem that the pixel signal is not accurately input to the liquid crystal display apparatus owing to the wiring delay of the cable for inputting the signal to the liquid crystal display apparatus. Therefore, the desired picture can not be displayed.